MXPA01001095A - Sunscreen compositions - Google Patents

Abstract

The present invention relates to compositions suitable for use as sunscreens which comprise a UVA sunscreen active and a carrier suitable for application to the skin. These compositions are substantially free of benzylidene camphor derivatives and provide excellent stability, efficiency, and UV protection efficacy in a safe, economical and aesthetically appealing manner. The compositions have a Sunscreen Efficiency Index of at least about 1.75, a UVA Efficacy Value of at least about 0.5, a UVA Photostability Index of at least about 0.85, a UVB Photostability Index of at least about 0.85, and a Transparency Value of less than about 10. Methods of using the compositions are also disclosed.

Description

COMPOSITIONS OF SOLAR FILTERS TECHNICAL FIELD The present invention relates to compositions suitable for use as a sunscreen, which have excellent efficiency, broad spectrum UV efficacy, photostability and transparency on the skin. The compositions comprising an active sunscreen compound that absorbs UVA and a suitable vehicle for application to the skin, are substantially free of benzylidenecamphor derivatives, and are characterized by having a sunscreen efficiency index of at least about 1.75, a UVA efficacy value of at least about 0.5, a UVA photostability index of at least about 0.85, an index of UVB photostability of at least about 0.85, and a value of transparency less than about 10.

BACKGROUND OF THE INVENTION It is well known that exposing yourself to sunlight can pose a number of risks to the skin. These damaging effects can result not only from sunbathing, but also from exposure to sunlight associated with daily outdoor activities. The greatest short-term risk of prolonged exposure to sunlight is erythema, ie sunburn, which ^^^^^^^ g ^^^^^^ g ^^ t ^ g ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^ results mainly from UV radiation having a wavelength of about 290 nm to about 320 nm. However, in the long term, malignant changes in the surface of the skin can often occur. Numerous epidemiological studies show a strong relationship between exposure to sunlight and human skin cancer. Another long-term risk of ultraviolet radiation is premature aging of the skin, which is caused mainly by UVA radiation having a wavelength of about 320 nm to about 400 nm. This condition is characterized by wrinkles and changes in the pigmentation of the skin, along with other physical changes such as cracks, telangiectasis, solar dermatosis, ecchymosis and loss of elasticity. Adverse effects associated with exposure to UV radiation are discussed more fully in DeSimone, "Sunscreen and Suntan Products," Handbook of Nonprescription Drugs, Seventh Edition, Chapter 26, p. 499-511 (American Pharmaceutical Association, Washington, D.C., 1982); Grove and Forbes, "A Method for Evaluating the Photoprotection Action of Sunscreen Agents Against UV-A Radiation," International Journal of Cosmetic Science, 4, p. 15-24 (1982); and the patent of E.U.A. No. 4,387,089, DePolo, issued June 7, 1983. As a result of the risks mentioned above, associated with exposure to sunlight, the general public's interest in the sunscreen product market has grown considerably. Today, not only are there sunscreen products for sunbathing, but there is also a variety of care products personal which also contains sunscreens, particularly cosmetic products which are used daily. "Personal care products" refers to auxiliary products for health and cosmetic beauty, generally recognized as formulated to beautify and care for the skin and hair. For example, personal care products include sunscreen products (for example, lotions, skin creams, etc.), cosmetics, toiletries, and pharmaceutical products whose sale does not require a prescription, made for topical use. Not surprisingly, consumers want sunscreen products, particularly everyday products, to be effective, aesthetically pleasing to their senses of sight and touch, and economical. Unfortunately, most commercially available sunscreen products have shortcomings in one or more of these areas. For example, most commercial sunscreens use high levels of active sunscreen compounds to achieve the desired levels of UV protection. These high levels of active sunscreen compounds not only increase the cost of the product, but also tend to contribute to the impoverishment of aesthetics (for example, bad feeling on the skin, whitening of the skin, etc.) and skin irritation. Many conventional sunscreen products are also deficient due to their inability to provide effective protection against broad spectrum UV radiation, ie protection against both UVB and UVA radiation. Currently, most sunscreen products commercially available are efficient in the absorption of UV radiation in the region of 290 nm to 320 nm UVB, so that the sunburn of the skin is prevented. They are less efficient when they absorb light which falls in the UVA region from 320 nm to 400 nm, which leaves the skin vulnerable to premature aging. This deficiency is due in part to the limited number of active sunscreen compounds that absorb UVA, which are both commercially available and approved for global use. A wide variety of active sunscreen compounds have been used in personal care products. It is desirable that the compound active solar filter or active system, provide broad spectrum UV protection, particularly protection against both UVA and UVB radiation. In addition, the active compound must be approved for human use, preferably on a global basis. It is also desirable that these active sunscreen compounds be formulated to provide filter products solar effective, stable, and aesthetically attractive. Dibenzoylmethane compounds are a class of sunscreen compounds, which provide broad spectrum UV protection and are approved for global use. Unfortunately, these sunscreens tend to photodegrade themselves when exposed to UV radiation, thus reducing its UVA efficiency. An approach to stabilize these types of sunscreens is described in the series of E.U.A. No. 07 / 929,612, Deckner, filed August 13, 1992, which involves the use of benzylidenecamphor sunscreens to stabilize the dibenzoylmethane compound. Without However, such compositions are not currently approved for global use. Another class of active sunscreen compounds known as physical sunblocks have also been used to provide skin protection against broad spectrum UV radiation. Physical sunscreens are inorganic compounds, which are believed to exert their effects by scattering, reflecting or absorbing UV radiation. See, Sayre, R.M. et al., "Physical Sunscreens," J. Soc. Cosmet. Chem., Vol. 41, no. 2, pp. 103-109 (1990). Unfortunately, when used at higher levels, they tend to leave an undesirable white film on the consumer's skin, and / or agglomerate in the finished product. The need for efficient and stable solar filter products (including photo-stable) persists, which provide broad-spectrum UV protection (ie against both UVA and UVB radiation), safely, economically and aesthetically attractive (transparency on the skin and low skin irritation). Now, it has been found that the compositions herein having a sunscreen efficiency index of at least about 1.75, a UVA efficacy value of at least about 0.5, a UVA photostability index of at least about 0.85, an index UVB photostability of at least about 0.85 and a transparency value of less than about 10, have excellent stability, efficiency, UV protection efficacy, safety, economy and aesthetics. < ca? t- < . v? iKilb &t? iiKi Mp. -efe_1 _ ^ _ ^ __ ^: ^ __ ^ _ ^ _ ¡rj | pE¡j gjJ BRIEF DESCRIPTION OF THE INVENTION The present invention relates to a composition suitable for use as a sunscreen comprising: a) A safe and effective amount of an active sunscreen component that absorbs UVA; b) A suitable vehicle for application to the skin; Wherein the composition is substantially free of benzylidenecamphor derivatives, and wherein the composition has a sunscreen efficiency index of at least about 1.75, a UVA efficacy value of at least about 0.5, a UVA photostability index of less about 0.85, a UVB photostability index of at least about 0.85, and a transparency value less than about 10. 15 In a preferred embodiment, the composition has a sunscreen efficiency index of at least about 2.0, a UVA efficiency value of at least about 0.5, a UVA photostability index of at least about 0.90, a UVB photostability index of at least about 0.90, and a transparency value less than about 20. In a more preferred embodiment, the composition has a sunscreen efficiency index of at least about 2.25, a UVA efficacy value of at least about 0.5, a photostability index. , < * «-. -3 > fet-bti¿- »and. The UVA of at least about 0.95, a UVB photostability index of at least about 0.95 and a transparency value of less than about 6.

DETAILED DESCRIPTION OF THE INVENTION The compositions of the present invention are useful for providing protection to human skin against the damaging effects of ultraviolet radiation. The essential components of these compositions are described below. Also included is a non-exclusive description of various optional and preferred components useful in embodiments of the present invention. The present invention may comprise, consist of, or consist essentially of any of the required or optional ingredients and / or limitations described herein. All percentages and ratios are calculated on a weight basis unless otherwise indicated. All percentages are calculated based on the total composition unless otherwise indicated. All molecular weights are weight average molecular weights and are given in units of grams per mole. All levels of ingredients are with reference to the active level of that ingredient, and are exclusive of solvents, by-products, or other impurities that may be present in commercially available sources, unless otherwise indicated. All measurements are made at room temperature, which is approximately 22.7 ° C, unless otherwise indicated. All documents referred to herein, including patents, patent applications and printed publications, are hereby incorporated by reference in their entirety in this description. By "safe and effective amount" is meant an amount of a compound, component or composition (as applicable) sufficient to significantly induce a positive effect (e.g., photoprotection or stability), but low enough to avoid serious side effects (for example, undue toxicity or allergic reaction), that is, provide a reasonable benefit to risk ratio, within the scope of a sound medical judgment.

UVA absorbing active sunscreen component The compositions of the present invention comprise an active UVA-absorbing sunscreen compound, which provides protection against UV radiation of wavelengths between 320 nm and 400 nm. Sunscreen compounds that absorb illustrative UVA suitable for use in the present invention include, but are not limited to, dibenzoylmethanes. These dibenzoylmethane sunscreen active compounds are described in the U.S.A. No. 4,489,057, issued to Welters et al. al., December 18, 1984, and the patent of E.U.A. No. 4,387,089, issued to Depolo on June 7, 1983; and in Sunscreens: Development, Evaluation, and Regulatory Aspects, edited by N.J. Lowe and N.A. Shaath, Marcel Dekker, Inc. (1990). Suitable dibenzoylmethane sunscreen compounds include those selected from the group consisting of 2-methyldibenzoylmethane, 4-methyldibenzoylmethane, 4-isopropyldibenzoylmethane, 4-tert-butyldibenzoylmethane, 2,4-dimethyldibenzoylmethane, 2,5-dimethyldibenzoylmethane, 4,4'- di-propylbenzoylmethane, 4- (1,1-dimethylethyl) -4'-methoxydibenzoylmethane, 2-methyl-5-isopropyl-4'-methoxydibenzoylmethane, 2-methyl-5-tert-butyl-4'-methoxydibenzoylmethane, 2,4 -dimethyl-4'-methoxydibenzoylmethane, 2,6-dimethyl-4'-tert-butyl-4'-methoxydibenzoylmethane, and mixtures thereof. Preferred dibenzoylmethane sunscreen compounds include those selected from the group consisting of 4- (, 1-dimethylethyl) -4'-methoxydibenzoylmethane, isopropyldibenzoylmethane, and mixtures thereof. A more preferred dibenzoylmethane sunscreen active compound is 4- (1,1-dimethylethyl) -4'-methoxydibenzoylmethane. The sunscreen active compound, 4- (1,1-dimethylethyl) -4'-methoxydibenzoylmethane, which is also known as butylmethoxydibenzoylmethane or Avobenzone, is commercially available under the names parsol® 1789 from Givaudan-Roure (International) S.A. (Basel, Switzerland) and Eusolex® 9020 from Merck & Co., Inc. (Whitehouse Station, NJ). The sunscreen 4-isopropyldibenzoylmethane, which is also known as ^ > ^^? r ..? The isopropyl dibenzoylmethane is commercially available from Merck under the name of Eusolex® 8020. The active UVA-absorbing sunscreen compound of the present invention is present in a safe and effective amount to provide broad spectrum UV protection, either independently or in combination with other UV protective active compounds which may be present in the composition, preferably from about 0.1% to about 10%, more preferably from about 0.2% to about 7%, and even more preferably from about 0.4% to approximately 5%. The exact amounts of the active sunscreen compound will vary depending on the desired sun protection factor, ie the "SPF" of the composition, as well as the desired level of UVA protection. (SPF is a commonly used measure of sunscreen protection against erythema.) SPF is defined as the ratio of ultraviolet energy to produce minimal erythema on protected skin, with respect to that required to produce the same minimal erythema on unprotected skin. the same individual, see Federal Register, 43, No. 166, pp. 38206-38269, August 25, 1978).

Vehicle The compositions of the present invention comprise a vehicle suitable for application to human skin. As used herein, a "suitable vehicle for application to human skin" means that , -Atofc ... ", -Jgs the vehicle and its components are suitable for use in contact with human skin without undue toxicity, incompatibility, instability, allergic response, and the like within the scope of a medical judgment or of the solid formulator. Such vehicles are well known to those skilled in the art, and may include one or more compatible liquid or solid filler vehicles or diluents, which are suitable for application to human skin. The vehicle may comprise one or more active or inactive materials, including but not limited to optional components described below. The vehicle comprises the balance of the composition. The compositions of the present invention preferably comprise from about 74% to about 99.7%, more preferably from about 79% to about 99%, of vehicle by weight of the composition. The vehicle can be formulated in several ways, including but not limited to emulsions (in emulsion technology, the term "dispersed phase" means that the phase exists as small particles or droplets that are suspended in and surrounded by a continuous phase). For example, suitable emulsions include emulsions of oil in water, water in oil, water in oil in water, oil in water in oil and oil in water in silicone. Preferred compositions comprise an oil in water emulsion. The compositions of the present invention can be formulated in a wide variety of product types, including creams, lotions, - - - - -.-s - ***. milks, foams, gel, oils, tonics and aerosols. Preferred compositions are formulated in lotions, creams, gels and aerosols. These product forms can be used for a number of applications, including, but not limited to, hand and body lotions, cleansing creams, facial moisturizers, anti-acne preparations, topical analgesics, makeups, including foundation and lipsticks, and the like. Any additional component required to formulate these products varies with the type of product, and is routinely chosen by a person skilled in the art. If the compositions of the present invention are formulated as an aerosol and applied to the skin as a spray product, a propellant is added to the composition. Examples of suitable propellants include chlorofluorinated hydrocarbons of lower molecular weight. A more complete description of propellants useful herein can be found in Sagarin, Cosmetics Science and Technology, second edition, Vol. 2, pp. 443-465 (1972).

Properties of the compositions of the invention The compositions of the present invention are characterized by having a sunscreen efficiency index of at least about 1.75, a UVA efficacy value of at least about 0.5, a UVA photostability index of at least about 0.85, a UVB photostability index of at least about 0.85, and a transparency value of less than about 10.

Preferred compositions are characterized by a sunscreen efficiency index of at least about 2.0, a UVA efficiency value of at least about 0.5, a UVA photostability index of at least about 0.90, a UVB photostability index of at least about 0.90, and a transfer value less than about 8. The most preferred compositions are characterized by a sunscreen efficiency ratio of at least about 2.25, a UVA efficiency value of at least about 0.5, a UVA photostability index of less about 0.95, a UVB photostability index of at least about 0.95, and a transparency value less than about 6. The above properties and methods for their determination are described below. a) sunscreen efficiency index The present compositions exhibit excellent efficiency. That is, a relatively low sunscreen active compound content provides relatively high SPF values. Therefore, the invention provides products that have improved safety, economy and aesthetic properties, including improved sensation and reduced potential irritation in relation to sunscreen compositions. This efficiency is defined by the sunscreen efficiency index of a composition, which is calculated as follows: efficiency index of SPF filter in vivo solar =% by weight of active compounds of solar filtration in the composition wherein the SPF in vivo is determined using the procedure described in the tentative final monogram of US sunscreens, issued in May 1993. This method of determining SPF in vivo involves the administration of a series of UV radiation exposures to the Subsite areas (measured in J / m2) on each subject with a precisely calibrated solar simulator. A series of 7 exposures is administered to protected test sites to determine the MED (PS), which is the MED of the protected skin (the MED is the minimum erythematous dose, which is the lowest dose of radiation that produces a uniform red that appears at the edges of the exposure site from 22 to 24 hours after exposure). The selected dose consists of a geometric series of 5 exposures, where the average exposure is placed to reach the expected SPF (as described in the monogram mentioned above) plus two more symmetrically placed exposures around the average exposure. The exact series of exposures that will be given to protected skin is determined by MED (US) (which is the MED of a non-protected / untreated control site) plus the expected SPF of the test sunscreen compositions. For compositions with an SPF less than 8, the exposures are MED (US) t sa m? t * > . * - «**. ., .. ,, .., ...-_ * _. ^ J ^ jl ^ ijj ^ g || ^ ^ i ^?. ^ ?? multiplied by 0.64X, 0.80X, 0.90X, 1.00X, 1.10X, 1.25X, and 1.56X, where X is equal to the expected SPF of the test product. For compositions with an expected SPF between 8 and 15, exposures are MED (US) multiplied by 0.69X, 0.83X, 0.91 X, 1.00X, 1.09X, 1.20X, and 1.44X, where X equals 5 Expected SPF of the test product. For compositions with an expected SPF greater than 15, the exposures are MED (US) multiplied by 0.76X, 0.87X, 0.93X, 1.00X, 1.07X, 1.15X and 1.32X, where X is equal to the expected SPF of the test product. The in vivo SPF value of the test sunscreen composition is calculated from the dose of UV radiation required to produce the MED of the protected skin, and from the dose of UV radiation required to produce the MED of the skin. skin not protected in the following way: otr - • MED (PS) SPE m VIV0 = MED (US) 5 where both MED (PS) and MED (US) are measured in J / nY (b) UVA efficacy value The compositions of the present invention exhibit improved UVA efficacy, as defined by the UVA efficacy value. The effectiveness value UVA of a composition is calculated from an absorbance curve of UV in vitro of a film of the synthetic collagen product.

Approximately 1 mg of product / cm2 of synthetic collagen is applied to the ^? ^? ^ K ^ j ^ side topography (ie, next texture) of a piece of synthetic hydrated collagen (eg, Vitro-Skin Innovative Measurement Solutions, Milford, CT), or an equivalent thereof, with a finger protected with a latex finger cover. The film of the product is allowed to dry at ambient conditions (22 ± 2 ° C) for 15 minutes. After 15 minutes of drying, the UV absorbance of the product film is determined using an analyzer Labsphere UV ultraviolet transmittance-1000S (Labsphere Inc., North Sutton, NH), or the equivalent thereof as follows. The reference absorbance measurements are taken on the side with untreated Vitro-Skin hydrated topography, using the Labsphere UV-1000S. The UV absorbance of the product film in treated collagen is measured at 8 different sites. The UV-1000S Labsphere subtracts the average reference absorbance from the average absorbency of the film into untreated collagen, and generates a UV absorbance curve of the test product film. Using the UV absorbance curve, the UVA efficiency value is calculated as follows: UVA efficiency value = UV Absorbance average film product in the UVA region (i.e., 320-400 nm) UV absorbency average film product in the UVB region (i.e., 290-320 nm) (c) UVA and UVB photostability indexes The compositions of the present invention exhibit improved photostability, showing very little or no change in UV absorbance upon UV exposure, as defined by their UVA and UVB photostability indices. The UVA and UVB photostability indices of a sunscreen product are determined by comparing an absorbance curve of a thin film before and after UV irradiation. First, an absorbance curve is generated for a film of a sunscreen, as described above in the UVA / UVB absorbance ratio method.

Once the absorbance curve is generated, the film layer is irradiated with approximately 2 J / cm2 per desired SPF unit of broadband UV radiation, for example, 30 J / cm2 required for SPF 15. A solar arc simulator Oriel 1000 W Xenon (Oriel Corp., Stratford, CT), whose output is filtered (for example, by dichroic mirrors, Oriel filters 81017 and 81018) use for irradiation. (An equivalent thereof can be used, which simulates the UV solar spectrum in the same way). Another absorbance curve for the product film is generated immediately after irradiation, as described in the UVA efficacy value method. The UVA and UVB photostability indexes are calculated from the absorbance curves and after UV irradiation, as follows: . .. ,,. . .. . ,,. , »Absorbency at 360 nm after UV irradiation, photostability index UVA - -: rr-r t,. - - -; - - Absorbency at 360 nm before UV irradiation. . ,,,,. ... . . , wr > Absorbency at 310 nm after UV Irradiation UVB photostability index -rr - ¡-: -r-r,. . • -. - - - rr-, Absorbency at 310 nm before UV irradiation (d) Transparency value The compositions of the present invention have low opacity, and therefore are relatively transparent when applied to the skin (i.e., they do not look white on the skin). The opacity is defined 5 by the transparency value, which is determined using an opacity graph (form 2A, Leneta Company of Manwah, NJ or the equivalent thereof) and a chromameter (e.g., a Minolta CR-200 chromameter , light source d65, 0 ° viewing angle, commercially available from Minolta Camera Co. of Ramsey, NJ, and described in the manual of the chromameter, Version 3.0, 1988, incorporated herein by reference, or the equivalent thereof). The opacity graph is half black (top) and half white (bottom), the colors being separated along a line parallel to the horizon. Approximately 8 grams of a test product are applied in an area of approximately 1.27 x 7.62 cm at the top of the graph of opacity. The product is distributed over the entire length of the card, through both halves and generally symmetrically, into a thin film using a 0.0038 cm film applicator (e.g., like that commercially available from BYK Garder of Columbia, Maryland. , or an equivalent thereof). The film is allowed to dry for 24 hours under conditions of 22 ° C +/- 2 ° C. Using the chromameter, the Y-trichromatic value of the product film (ie, the XYZ color space of the film) is measured and recorded in three different areas of the product film on the black section of the opacity graph, and also in three different areas of the product film on the white section of the opacity graph. Suitable areas for measurement are those that have a uniform distribution of the product over the area. The value of transparency is calculated as the mathematical average of the three trichromatic values Y on the black areas, divided by the mathematical average of the three trichromatic values Y on the white areas, multiplied by 100 in the following way: Transparency value neqr0 Promed! ° X 10n Ybiap8 average Optional Components The compositions of the present invention may contain a variety of other ingredients such as those conventionally used in a given type of product, provided they do not unacceptably alter the benefits of the invention. These optional components should be suitable for application to human skin, i.e., when incorporated into the composition, they are suitable for use in contact with human skin without undue toxicity, incompatibility, instability, allergic response and the like, within the scope of a medical judgment or solid formulator. The CTFA Cosmetic Ingredient Handbook, second edition (1992) describes a wide variety of non-limiting cosmetic and pharmaceutical ingredients, commonly used in the skin care industry, which are suitable for use in the compositions of the present invention. Examples of these kinds of ingredients include: abrasives, absorbers, aesthetic components such as fragrances, pigments, colorations / colorants, essential oils, sensitizers for the skin, astringents, etc. (for example, clove oil, menthol, camphor, eucalyptus oil, eugenol, menthyl lactate, Hamamelis Virginiana distillate), anti-acne agents (eg, resorcinol, sulfur, salicylic acid, erythromycin, zinc, etc.) , cake antifouling agents, antifoaming agents, antimicrobial agents (eg, iodopropyl butyl carbamate) antioxidants, binders, biological additives, pH regulating agents, bulking agents, chelating agents, chemical additives, dyes, astringents, biocides cosmetics, denaturants, drug astringents, external analgesics, film formers or materials, for example, polymers to aid the film-forming properties and substantially the composition (e.g., eicosene and vinyl pyrrolidone copolymer), humectants, agents opacifiers, pH adjusters, propellants, reducing agents, sequestrants, skin whitening agents (or age clarifying agents) (eg, hydroquinone, kojic acid, ascorbic acid, magnesium ascorbyl phosphate, ascorbyl glucosamine), skin conditioning agents (humectants, including miscellaneous and occlusive), sedative and / or skin healing agents (e.g. , panthenol and derivatives, such as ethyl panthenol), aloe vera, pantothenic acid and its derivatives, allantoin, bisabolol and dipotassium glycyrrhizinate), skin treating agents including agents to prevent, retard, counteract and / or reverse wrinkles of the skin (for example, ^^^ ^^^ ^ ^^^^? ^ ttr ^^ * ^^? »s ^^^^^^^? ^^ '' ^ f. ^^^ J j ^ jg alpha-hydroxy acids such as lactic acid and cholic acid, and beta-hydroxy acids such as salicylic acid), thickeners, and vitamins, and derivatives thereof (for example, tocopherol, tocopherol, retinoic acid, retinol, retinoids, retinyl palmitate, niacin, niacinamide and the like). The compositions of the present invention may contain one or more of these optional components. Preferred compositions optionally contain one or more materials selected from the active UVB sunscreen compounds, anti-acne active compounds, artificial tanning agents, humectants, moistening agents, skin conditioners and thickeners / structuring agents. (a) Active sunscreen composition The compositions of the present invention may comprise an active UVB sunscreen compound, which absorbs UV radiation that has a wavelength of about 290 nm to about 320 nm. As used herein, the sunscreen active compound UVB means an active compound other than the active sunscreen compound of dibenzoylmethane, which itself may possess UVB absorption properties. The compositions should comprise an amount of the active compound UVB effective to provide UVB protection, either independently or in combination with other UV protective compounds, which may be present in the composition, preferably from about 0.1% to about 10%, more preferably from about 0.1% to about 4%, and even more preferably from about 0.5% to 2.5% by weight of the composition. A wide variety of UVB sunscreen active compounds, including both organic sunscreen active compounds and inorganic physical sun blockers, are suitable for use herein. Non-limiting examples of such active sunscreen compounds are described in the US patent. No. 5,087,445, issued February 11, 1992 to Haffey et al; and the patent of E.U.A. No. 5,073,371 and No. 5,073,372, both issued December 17, 1991 to Turner et al. Non-limiting examples of suitable physical sunblocks are described in CTFA International Cosmetic Ingredient Dictionary, sixth edition 1995, pp. 1026-28 and 1103. Preferred UVB sunscreen active compounds are selected from the group consisting of 2-phenyl-benzimidazole-5-sulfonic acid, octocrylene, TEA salicylate, octyl dimethyl PABA, zinc oxide, titanium dioxide and mixtures thereof. A preferred organic sunscreen active compound is 2-phenyl-benzimidazole-5-sulfonic acid, while preferred inorganic physical sunblocks are zinc oxide, titanium dioxide and mixtures thereof. Salts and acid-neutralized forms of acid sunscreens are also contemplated herein. When used, physical sunscreens are present in an amount such that the present compositions are transparent on the skin (ie, do not turn white), preferably on the skin. - ^ -iifirtü-ft • * • - * m '^^ MflfiiM ^ irrti "^" * ^ - "- * *** >. ^^. ^ an amount less than or equal to approximately 5%. it uses titanium dioxide, it may have an anatase, rutile or amorphous structure Physical particle blockers, for example, titanium dioxide and zinc oxide, may be covered or not covered with a variety of materials including, but not limited to. they are limited to amino acids, aluminum compounds such as alumina, aluminum stearate, aluminum laurate and the like, carboxylic acids and their salts, for example, stearic acid and its salts, phospholipids such as lecithin, organic silicone compounds, silicone compounds inorganics such as silica and silicates, and mixtures thereof A preferred titanium dioxide is commercially available from Tayca (Japan) and is distributed by Tri-K Industries (Emerson, NJ) under the micronized MT series (eg, MT 100SAS). b) Anti-acne active compounds The compositions of the present invention may comprise one or more anti-acne active compounds. Examples of useful anti-acne active compounds are described in more detail in the US patent. No. 5,607,980 issued to McAtee et al. On March 4, 1997.

C) Artificial bronzing agents The compositions of the present invention may comprise one or more artificial bronzing agents. Suitable bronzing agents include dihydroxyacetone, tyrosine, tyrosine esters and fofo-fo- - * - - • * - * ^^ .. ^ ?? a ^. jr m r _, ....., - -? lmiM¡Éi.Íl.i ^ DOPA. See The Merck Index, tenth edition, entry 3167, p. 463 (1983), and "Dihydropxyacetone for Cosmetics", E. Merck Technical Bullletin, 03-304 110, 319 897, 180 588. c) Structuring agent The compositions of the present invention may contain a structuring agent. Structurants are particularly preferred in the water-in-oil emulsions of the present invention. Without being limited by theory, it is believed that the structuring agent helps to provide rheological characteristics to the composition, which contribute to the stability of the composition. For example, the structuring agent tends to assist in the formation of liquid crystal gel network structures. The structuring agent can also function as an emulsifier or a surfactant. Preferred compositions of this invention comprise from about 0.5% to about 20%, more preferably from about 1% to about 10%, and even more preferably from about 1% to about 5%, of one or more structuring agents. The preferred structuring agents of the present invention are selected from the group consisting of stearic acid, palmitic acid, stearyl alcohol, cetyl alcohol, behenyl alcohol, stearic acid, palmitic acid, the polyethylene glycol ether of stearyl alcohol having an average of about 1 to approximately 21 oxide units Mt *? T? MßM * M, * £ m. of ethylene, the polyethylene glycol ether of cetyl alcohol having an average of about 1 to about 5 ethylene oxide units, and mixtures thereof. More preferred structuring agents of the present invention are selected from the group consisting of stearyl alcohol, cetyl alcohol, behenyl alcohol, the polyethylene glycol ether of stearyl alcohol having an average of about 2 ethylene oxide units (steareth-2), the polyethylene glycol ether of stearyl alcohol having an average of about 21 units of ethylene oxide (steareth-21), the polyethylene glycol ether of cetyl alcohol having an average of about 2 units of ethylene oxide, and mixtures thereof. same. Even more preferred structuring agents are selected from the group consisting of stearic acid, palmitic acid, stearyl alcohol, cetyl alcohol, behenyl alcohol, steareth-2, steareth-21, mixtures thereof.

D) Thickening agent (including thickeners and gelling agents) The compositions of the present invention may comprise one or more thickening agents, preferably from about 0.1% to about 5%, more preferably from about 0.1% to about 3%, and even more preferably from about 0.25% to about 2%, by weight of the composition. Non-limiting classes of thickening agents include those selected from the group consisting of: (i) Carboxylic acid polymers These polymers are crosslinked compounds containing one or more monomers derived from acrylic acid, substituted acrylic acids and salts and esters of these acrylic acids and substituted acrylic acids, wherein the crosslinking agent contains two or more carbon-carbon double bonds, and it is derived from a polyhydric alcohol. Polymers useful in the present invention are described in full form in the U.S. patent. No. 5,087,445 to Haffey et al., Issued February 11, 1992; the patent of E: U.A. No. 4,509,949 of Huang et al., Issued April 5, 1985, the patent of E.U.A. No. 2,798,053 of Brown, issued July 2, 1957; and in CTFA International Cosmetic Ingredient Dictionary, fourth edition, 1991, pp. 12 and 80. Examples of commercially available carboxylic acid polymers useful herein include carbomers, which are homopolymers of acrylic acid crosslinked with allyl ethers of sucrose or pentaerythritol. Carbomers are available as the Carbopol® 900 series from B.F. Goodrich (for example, Carbopol® 954). In addition, other suitable carboxylic acid polymeric agents include copolymers of C10-30 alkyl acrylates with one or more acrylic acid monomers, acid methacrylic, or one of its short chain esters (ie, C? -4 alcohol), wherein the interlacing agent is an allyl ether of sucrose or pentaep'tritol. These copolymers are known as crosslinked polymers of C?-3o alkyl acrylates / acrylates, and are commercially available as Carbopol® t ^ a- ^ tefaagi ^^ a ^ Mf gi ^^^ ** 6 ^ 1342, Carbopol® 1382, Pemulen TR-1, and Pemulen TR-2, from B.F. Goodrich. In other words, examples of carboxylic acid polymer thickeners useful herein, are those selected from the group consisting of carbomers, crosslinked polymers of C-io-C3o alkyl acrylates / acrylates, and mixtures thereof. (ii) Interlaced polyacrylate polymers The compositions of the present invention may optionally comprise entangled polyacrylate polymers useful as thickeners or gelling agents, including both cationic and non-ionic polymers, the cationic being generally preferred. Examples of interlaced nonionic polyacrylate polymers and crosslinked cationic polyacrylate polymers are those described in the U.S.A. No. 5,100,660 to Hawe et al., Issued March 31, 1992; the patent of E.U.A. No. 4,849,484, issued July 18, 1989; the patent of E.U.A. No. 4,835,206 to Farrar et al., Issued March 30, 1989; the patent of E.U.A. No. 4,628,078 to Glover et al., Issued December 9, 1986; the patent of E.U.A. No. 4,599,379 to Flesher et al., Issued July 8, 1986; and EP 228,868 to Farrar et al., published July 15, 1987. (iii) Polyacrylamide Polymers The compositions of the present invention may optionally comprise polyacrylamide polymers, especially polymers of nonionic polyacrylamides, including branched or unbranched substituted polymers. Most preferred among these polyacrylamide polymers is the nonionic polymer with the designation CTFA as polyacrylamide and isoparaffin and laureth-7, available under the tradename Sepigel 305 from Seppic Corporation (Fairfield, NJ). Other polyacrylamide polymers useful herein include multiblock copolymers of acrylamides and substituted acrylamides with acrylic acids, and substituted acrylic acids. Commercially available examples of these multiblock copolymers include Hypan SR150H, SS500V, SS500W, SSSA100H from Lipo Chemicals, Inc., (Patterson, NJ).

(V) Polysaccharides A wide variety of polysaccharides is useful herein, "polysaccharides" refers to gelling agents, which contain a base structure of repeated sugar units (ie, carbohydrates). Non-limiting examples of polysaccharide gelling agents include those selected from the group consisting of cellulose, carboxymethyl, hydroxyethylcellulose, cellulose acetate, propionate, carboxylate, hydroxyethylcellulose, hydroxyethyl ethylcellulose, hydroxypropylcellulose, hydroxypropyl methylcellulose, methylhydroxyethylcellulose, miraclecrystalline cellulose, sodium cellulose sulfate , and mixtures thereof. Also substituted alkylcelluloses are useful herein. In these polymers, the hydroxy groups of the cellulose polymer are hydroxyalkylated (preferably hydroxyethylated or hydroxypropylated), to form a hydroxyalkylated cellulose which is then modified with a straight or branched chain alkyl group of C10-C30, through an ether linkage. Typically, these polymers are straight or branched chain alcohol ethers of C 0 -C 30 with hydroxyalkyl celluloses. Examples of alkyl groups useful herein include those selected from the group consisting of stearyl, isostearyl, lauryl, myristyl, cetyl, isocetyl, cocoyl (i.e., alkyl groups derived from the coconut oil alcohols), palmityl, oleyl, linoleyl , linolenyl, ricinolenyl, behenyl, and mixtures thereof. Among the alkylhydroxyalkylcellulose ethers, the material with the CTFA designation of cetylhydroxyethylcellulose, which is the ether of the cetyl alcohol and hydroxyethylcellulose, is preferred. This material is sold under the trade name Natrosol® CS Plus from Aqualon Corporation (Wilmington, DE). Other useful polysaccharides include scleroglucans, which comprise a linear chain of linked glucose units (1-3) with a linked glucose (1-6) every three units, of which a commercially available example is (Clearogel ™ CS11 from Michel Mercier Products Inc. (Mountainside, NJ). (v) Gums Other thickeners and gelling agents useful herein include materials that are derived primarily from natural sources. Non-limiting examples of these gum agents include .. ^^^ á ^^^ i ^^. ,, ... ^ ?? * Í.? **? A * A + J. .. «**. materials selected from the group consisting of acacia, agar, algin, alginic acid, ammonium alginate, amylopectin, calcium alginate, calcium carrageenan, carnitine, carrageenan, dextrin, gelatin, gellan gum, guar gum, guar hydroxypropyltrimonium chloride, hectorite, hyaluronic acid, hydrated silica, hydroxypropylchitosan, hydroxypropyloguar, karaya gum, kelp, locust bean gum, natto gum, potassium alginate, potassium carrageenan, propylene glycol alginate, sclerotium gum, sodium carboxymethyldextran, sodium carrageenan, gum of tragacanth, xanthan gum and mixtures thereof. Preferred compositions of the present invention include a thickener selected from the group consisting of carboxylic acid polymers, crosslinked polyacrylate polymers, polyacrylamide polymers and mixtures thereof, most preferably selected from the group consisting of carboxylic acid polymers, polyacrylamide polymers and mixtures thereof. e) Moisturizers, moisturizers and skin conditioners Preferred compositions optionally comprise one or more skin moisturizers, moisturizers or conditioners. A variety of these materials may be employed, and each may be present at a level of from about 0.01% to about 20%, more preferably from about 0.1% to about 10%, and even more preferably from about 0.5% to about 7%.

«G = ^^ gfe £ * ^^^? Ga ^ ^^^^ ¡^ ^ ^^^^^^^^^^^^^^^^^^^^ These materials include, but are not limited to, guanidine.; glycolic acid and glycolate salts (for example, ammonium and quaternary alkylammonium); lactic acid and lactate salts (for example ammonium and quaternary alkylammonium); aloe vera in any of its variety of forms (for example, aloe vera gel); polyhydroxy alcohols such as sorbitol, glycerol, hexanetriol, propylene glycol, butylene glycol, hexylene glycol and the like; polyethylene glycols; sugars and starches; sugar and starch derivatives (eg, alkoxylated glucose); hyaluronic acid; lactamide monoethanolamine; acetamide monoethanolamine; and mixtures thereof. Also useful herein are the propoxylated glycerols disclosed in U.S. Patent No. 4,976,953, to Orr et al., Issued December 11, 1990. Various monoesters of CrC30 and polyesters of sugars and related materials are also useful. These esters are derived from a sugar or polyol portion, and one or more carboxylic acid moieties. Such ester materials are described in additional form in the patent of E.U.A. No. 2,831, 854, in the patent of E.U.A.No. 4,005,196 of Jandacek, issued on January 25, 1977; patent of E.U.A.No. 4,005,195, by Jandacek, issued on January 25, 1977; patent of E.U.A. 5,306,516, Letton et al., Issued April 26, 1994; patent of E.U.A. No. 5,306,515, to Letton et al., Issued April 26, 1994; patent of E.U.A. No. 5,305,514 to Letton et al., Issued April 26, 1994; patent of E.U.A. No. 4,797,300, Jandacek et al., Issued January 10, 1989; patent of E.U.A. No. 3,963,699, Rizzi et al., Issued June 15, 1976; patent ¿M ^ ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ **? * tii of E.U.A. No. 4,518,772, Volpenhein, issued May 21, 1985; patent of E.U.A. No. 4,517,360, Volpenhein, issued May 21, 1985. f) Emulsifiers The compositions of the present invention may also comprise one or more emulsifiers. Emulsifiers generally serve to reduce the interfacial tension between phases and improve the formulation and stability of an emulsion. Suitable emulsifiers include a wide variety of nonionic, cationic, anionic and zwitterionic emulsifiers. See McCutcheon's Detergents and Emulsifiers, North American edition (1986), published by Allured Publishing Corporation; patent of E.U.A. No. 5,011, 681 issued to Ciotti et al, on April 30, 1991; patent of E.U.A. No. 4,421, 769 issued to Dixon et al, on December 20, 1983; and patent of E.U.A. No. 3,755,560 issued to Dickert et al, on August 28, 1973. Types of suitable emulsifiers include glycerin esters, propylene glycol esters, polyethylene glycol fatty acid esters, polypropylene glycol fatty acid esters, sorbitol esters, anhydride esters sorbitan, carboxylic acid copolymers, glucose esters and ethers, ethoxylated ethers, ethoxylated alcohols, alkyl phosphates, fatty ether polyoxyethylene phosphates, fatty acid amides, acyl lactylates, soaps and mixtures thereof. ~ i i ¡* ^ .. - _... ^ ". ^^ .. 1l ^ f ^ ft? A? ^ Ír? ?? r-g ^ jBife ^^ - ^ - • - • < ^^^^^ Suitable emulsifiers may include, but are not limited to TEA stearate, DEA oleth-3 phosphate, polyethylene glycol 20-sorbitan monolaurate (polysorbate 20), polyethylene glycol 5-soy star, steareth-2, stteareth-20 , steareth-21 ceteareth-20, PPG-2 distearate ether PGG-2 5 methyl glucose, ceteth-10, polysorbate 80, cetyl phosphate, potassium cetyl phosphate, diethanolamine cetyl phosphate, polysorbate 60, glyceryl stearate, PEG-100 stearate and mixtures thereof. Preferred emulsifiers are steareth-2, steareth-21, stearate of TEA, diethanolamine cetylphosphate, potassium cetyl phosphate, and mixtures thereof. The emulsifier can be used individually or as a mixture of two or more, and comprises from about 0.1% to about 10%, more preferably from about 0.15% to about 7%, and even more preferably from about 0.25 to about 5% of the compositions herein invention. Although a variety of optional components can be included in the present compositions, the compositions are substantially free of benzylidenecamphor derivatives. As used herein, "substantially free of benzylidene camphor" means that the present compositions comprise less than about 0.1% of benzylidene camphor. Preferred compositions comprise less than about 0.05% benzylidene camphor. Most preferably, the compositions are essentially free of benzylidene camphor, ie they do not contain detectable benzylidene camphor.

Methods for protecting the skin from UV radiation The compositions of the present invention are suitable for use as a sunscreen to provide protection to human skin from the damaging effects of UV radiation, which include but are not limited to sunburn and premature aging of the skin. Therefore, the present invention also relates to methods for protecting human skin from the damaging effects of UV radiation. Such methods generally involve attenuating or reducing the amount of UV radiation, which reaches the surface of the skin. To protect the skin from UV radiation, a safe and effective (photoprotective) amount of the composition is applied topically to the skin. "Topical application" refers to the application of the present compositions by dispersion, spraying, etc. on the surface of the skin. The exact amount applied may vary depending on the level of UV protection desired. Typically about 0.5 mg of composition per cm2 of skin is applied to approximately 25 mg of composition per cm2 of skin. = ^ Ñ ñ ñ ñ ii ii ii? IMii n f + *** »** - < * - EXAMPLES The following examples further describe and demonstrate the embodiments within the scope of the present invention. The five examples are given solely for the purpose of illustration, and should not be taken as limitations of the present invention, as many variations of the present are possible without departing from the spirit and scope of the invention. The following sunscreen products are representative of the present invention. fifteen twenty g ^^ ^ s ^^^ Sá ^^ ^^ s ^^ ^ - ---. The aqueous phase is prepared by mixing in a suitable vessel, the Carbomer 954 and the crosslinked polymer of C 0 -C 3 alkyl acrylate / acrylates in all the water minus 4%. Butylene glycol, glycerin, disodium EDTA, and methyl paraben are added to the aqueous phase, and heated 5 to 80 ° C. The oil phase is prepared in a separate vessel by mixing the isopropyl palmitate, butylmethoxydibenzoylmethane, octocrylene, propylparaben, DEA cetylphosphate, stearic acid, cetyl alcohol, stearyl alcohol, and eisplane copolymer of PVC, and heating at 80 ° C. When both phases reach 80 ° C, the oil phase to the aqueous phase while milling the system to form an emulsion. The system is cooled under agitation. Once the system reaches 70 ° C, a premix containing 0.73% of triethanolamine and 1% of water is added to the load. When the charge is cooled to about 45 ° C, a premix containing the phenylbenzimidazole sulfonic acid, the The remaining triethanolamine and the remaining water to the load are cooled to 30 ° C and poured into suitable containers.

Claims (10)

NOVELTY OF THE INVENTION CLAIMS

1. A composition suitable for use as a sunscreen, characterized in that it comprises: a) a safe and effective amount of an active UVA sunscreen compound; and b) a vehicle suitable for application to the skin; wherein the composition is substantially free of benzylidenecamfor derivatives, and has a sunscreen efficiency index 10 of at least 1.75, a UVA efficacy value of at least 0.5, a UVA photostability index of at least 0.85, an index of UVB photostability of at least 0.85 and a transparency value of less than 10.

2. The composition according to any of the preceding claims, further characterized in that it has an index of sunscreen efficiency of at least 2.0.

3. The composition according to any of the preceding claims, further characterized in that it has a sunscreen efficiency index of at least 2.25.

4. The composition according to any of the preceding claims, further characterized in that it has a sunscreen efficiency index of at least 2.5.

5. - The composition according to any of the preceding claims, further characterized in that it has a UVA efficiency value of at least 0.55.

6. The composition according to any of the preceding claims, further characterized in that it has a UVA photostability index of at least 0.95.

7. The composition according to any of the preceding claims, further characterized in that it has a UVA photostability index of at least 0.90.

8. The composition according to any of the preceding claims, further characterized in that it has a UVB photostability index of at least 0.90.

9. The composition according to any of the preceding claims, further characterized in that it has a transparency value of less than 8.

10. The composition according to any of the preceding claims, further characterized by having a transparency value less than 6